笔石是笔石动物的化石，由于其保存状态是压扁成了碳质薄膜，很像铅笔在岩石层上书写的痕迹，因此才被科学家叫做“笔石”。
...笔石;;沉积间断;;奥陶系;;志留系;;恩施;;湖北 [gap=1607]Keywords: biostratigraphy,lithostratigraphy,depositional hiatus,graptolites,Ordovician,Silurian,Enshi,Hubei ...
基于262个网页-相关网页
该笔石动物群属于华南型的珠江亚型，具有典型的太平洋型动物群的特点。
The graptolite fauna belongs to the Zhujiang sub-form of Huanan form with typical characteristics of the Pacific graptolite fauna.
应用反射率十字图解研究了中国部分地区下古生界地层中动物有机碎屑笔石的光学各向异性。
The optical anisotropy of zooclast graptolite in some Paleozoic strata of China has been studied using reflectance cross-plot analysis.
在奥陶纪，大多数生命都生活在海洋里，所以海洋生物，例如三叶虫、腕足类动物与笔石动物的数量在此时急剧减少。
During the Ordovician, most life was in the sea, so it was sea creatures such as trilobites, brachiopods and graptolites that were drastically reduced in number.
应用推荐